i have found a used kasco pond areator thats a 1/2 horse power it was used for 1 month to keep ice off a lake would it be good for my 1/2 acre pond and whats it worth

Is it a surface agitator or a circulator? I have both.

Does it look like this?

1/2 HP circulator

....or this?

Bruce Condello -

yes thats exactly what it is
whats one worth thats been used one season
would it be as good as a bottom areator

Yes, the 1/2 hp "circulator" should aerate the entire water column, and destratify a 1/2 acre pond if you run it 24/7. My 3/4 hp circulator aerated my 1.25 acre pond easily. Remember that circulation is simply the ability to expose most or all of your water to atmospheric diffusion of oxygen into the water. I extensively tested the O2 levels in my pond, and essentially what happens is that you dampen the highs and lows of O2 by constantly mixing. If your Kasco is a surface agitator then it will give you super high O2, but only in a very limited area near the unit, so I would only consider it an emergency refuge for fish in a DO crash.

I believe the warranty is at least three years on these units. Have you established if your warranty is still intact on the unit you wish to purchase? I believe you can find this new on the internet for somewhere in the 700 dollar range, so a guess would be that you would come out OK if you paid somewhere around 500-550 bucks. I'd pay that anyway.

Honestly, I'm just taking a stab at that number. Some of the aeration experts on this forum will forget more about aeration today than I'll know in my entire lifetime.

Anybody else?

really depends on depth and shape of your pond to use this as bottom diffuser. If you can get that used for $500 in good shape Bruce is right that is a good price. We have a client still running his Kasco 1/2 hp purchased in 1998.